119 lines
2.9 KiB
Go
119 lines
2.9 KiB
Go
/*
|
|
Copyright The containerd Authors.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
|
|
package runc
|
|
|
|
import (
|
|
"os/exec"
|
|
"runtime"
|
|
"syscall"
|
|
"time"
|
|
)
|
|
|
|
// Monitor is the default ProcessMonitor for handling runc process exit
|
|
var Monitor ProcessMonitor = &defaultMonitor{}
|
|
|
|
// Exit holds the exit information from a process
|
|
type Exit struct {
|
|
Timestamp time.Time
|
|
Pid int
|
|
Status int
|
|
}
|
|
|
|
// ProcessMonitor is an interface for process monitoring.
|
|
//
|
|
// It allows daemons using go-runc to have a SIGCHLD handler
|
|
// to handle exits without introducing races between the handler
|
|
// and go's exec.Cmd.
|
|
//
|
|
// ProcessMonitor also provides a StartLocked method which is similar to
|
|
// Start, but locks the goroutine used to start the process to an OS thread
|
|
// (for example: when Pdeathsig is set).
|
|
type ProcessMonitor interface {
|
|
Start(*exec.Cmd) (chan Exit, error)
|
|
StartLocked(*exec.Cmd) (chan Exit, error)
|
|
Wait(*exec.Cmd, chan Exit) (int, error)
|
|
}
|
|
|
|
type defaultMonitor struct{}
|
|
|
|
func (m *defaultMonitor) Start(c *exec.Cmd) (chan Exit, error) {
|
|
if err := c.Start(); err != nil {
|
|
return nil, err
|
|
}
|
|
ec := make(chan Exit, 1)
|
|
go func() {
|
|
var status int
|
|
if err := c.Wait(); err != nil {
|
|
status = 255
|
|
if exitErr, ok := err.(*exec.ExitError); ok {
|
|
if ws, ok := exitErr.Sys().(syscall.WaitStatus); ok {
|
|
status = ws.ExitStatus()
|
|
}
|
|
}
|
|
}
|
|
ec <- Exit{
|
|
Timestamp: time.Now(),
|
|
Pid: c.Process.Pid,
|
|
Status: status,
|
|
}
|
|
close(ec)
|
|
}()
|
|
return ec, nil
|
|
}
|
|
|
|
// StartLocked is like Start, but locks the goroutine used to start the process to
|
|
// the OS thread for use-cases where the parent thread matters to the child process
|
|
// (for example: when Pdeathsig is set).
|
|
func (m *defaultMonitor) StartLocked(c *exec.Cmd) (chan Exit, error) {
|
|
started := make(chan error)
|
|
ec := make(chan Exit, 1)
|
|
go func() {
|
|
runtime.LockOSThread()
|
|
defer runtime.UnlockOSThread()
|
|
|
|
if err := c.Start(); err != nil {
|
|
started <- err
|
|
return
|
|
}
|
|
close(started)
|
|
var status int
|
|
if err := c.Wait(); err != nil {
|
|
status = 255
|
|
if exitErr, ok := err.(*exec.ExitError); ok {
|
|
if ws, ok := exitErr.Sys().(syscall.WaitStatus); ok {
|
|
status = ws.ExitStatus()
|
|
}
|
|
}
|
|
}
|
|
ec <- Exit{
|
|
Timestamp: time.Now(),
|
|
Pid: c.Process.Pid,
|
|
Status: status,
|
|
}
|
|
close(ec)
|
|
}()
|
|
if err := <-started; err != nil {
|
|
return nil, err
|
|
}
|
|
return ec, nil
|
|
}
|
|
|
|
func (m *defaultMonitor) Wait(c *exec.Cmd, ec chan Exit) (int, error) {
|
|
e := <-ec
|
|
return e.Status, nil
|
|
}
|